https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86908
--- Comment #5 from Kostya Frumkin <fro0m.spam at gmail dot com> --- (In reply to Jonathan Wakely from comment #4) > (In reply to Kostya Frumkin from comment #3) > > Hi, for example msvc2013 calls base class's virtual method when msvc2015 > > calls derived class's virtual method. > > It's undefined behaviour. Anything can happen. > > > This is developer's mistake which can be predicted by compiler. Few > > developers know about this behavior. > > Using placement new to replace a polymorphic type is not a common idiom, I > don't think it's worth adding a warning about it. Just don't do it. > > > It'd be awesome to see the correct behavior or at least warning that base > > method is being used after placement new. > > GCC's behaviour is already correct. It is best way to get away with heap allocation in many cases. Let's make a warning about undefined behavior.
